Conventional aluminum-magnesium casting alloys have many attractive properties, such as high ultimate tensile strength (>170 MPa) and elongation (>8%) with moderate yield strength (>120 MPa). However, there is a demand for aluminum cast alloys combining improved mechanical properties with a good corrosion resistance.
Some disclosures of aluminum-magnesium casting alloys found in the prior art literature will be mentioned below.
WO-96/15281 discloses a casting alloy consisting of, in weight percent:                Mg 3.0-6.0        Mn 0.5-2.0        Ti<0.2        Fe<0.15        Si 1.4-3.5        balance aluminum and impurities.The alloy may be used in a die-casting operation, and appears to be particularly suitable for use in thixocasting and rheocasting operations.        
WO-96/25528 discloses a casting alloy consisting of, in weight percent:                Mg 2.5-4.5, preferably 2.7-3.0        Mn<0.6, preferably 0.2-0.6        Fe<0.6        Si<0.45        Cu<0.10        Be<0.003, preferably <0.001        balance aluminum and impurities.Optionally the alloy may further comprise 0.01-0.04% Ti and/or 0.01-0.10% Zn. The alloy can be employed in die-casting operations, the alloy is capable of having a yield strength greater than or equal to 110 MPa and an elongation greater than or equal to 17%.        
WO-96/30554 discloses a casting alloy consisting of, in weight percent:                Mg 2.0-5.0, preferably 2.5-4.0        Mn 0.2-1.6, preferably 0.4-0.8        Zr 0.1-0.3        Fe<1.0        Si<0.3        balance aluminum and impurities.The alloy may be used in die-casting operations. The casting alloy is particularly suitable for manufacturing safety components for cars. Typical strength levels disclosed in a T5-temper are YS of 116 MPa and UTS of 219 MPa and elongation of 19%.        
JP-A-09-003582 discloses an aluminum casting alloy having, in weight percent:                Mg 3.0-5.5        Zn 1.0-2.0, such that Mg/Zn-ratio is 1.5-5.5        Mn 0.05-1.0        Cu 0.05-0.8        Fe 0.10-0.8        balance aluminum and inevitable impurities.The cast products have in its matrix dispersed crystallised products in a spheroidising way.        